*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
body{
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(to top left,#ffe29f,#ffa99f,#ff719a);
    overflow: hidden;
}
.container{
    text-align: center;
    color: #fff;
}
.container h1{
    font-size: 50px;
    letter-spacing: 3px;
    font-weight: 100;
    margin-top: 15px;
}
.bg-squares{
    list-style: none;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}
.bg-squares li{
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.15);
    position: absolute;
    bottom: -160px;
    animation: square 2s linear infinite ;
}
.bg-squares li:nth-child(1){
    left: 10%;
}
.bg-squares li:nth-child(2){
    left: 10%;
    width: 80px;
    height: 80px;
    /* 延迟时间 */
    animation-delay: 2s;
    /* 动画持续时间 */
    animation-duration: 17s;
}
.bg-squares li:nth-child(3){
    left: 25%;
    animation-delay: 4s;
}
.bg-squares li:nth-child(4){
    left: 40%;
    width: 60px;
    height: 60px;
    background-color: rgba(255, 255, 255, 0.25);
    animation-duration: 22s;
}
.bg-squares li:nth-child(5){
    left: 70%;
}
.bg-squares li:nth-child(6){
    left: 80%;
    width: 120px;
    height: 110px;
    background-color: rgba(255, 255, 255, 0.2);
    animation-delay: 3s;
}
.bg-squares li:nth-child(7){
    left: 33%;
    width: 160px;
    height: 160px;
    animation-delay: 7s;
}

/* 关键帧动画 */
@keyframes square{
    0%{
        transform: translateY(0);
    }
    100%{
        /* 旋转六百度，垂直移动 */
        transform: translateY(-120vh) rotate(600deg);
    }

}
